What test is most helpful to confirm the diagnosis of multiple sclerosis?

• A. MRI with gadolinium showing white matter plaques
• B. Lumbar puncture with oligoclonal bands in CSF
• C. EEG demonstrating periodic sharp waves
• D. CT scan without contrast

Answer: (A)

Diagnosing MS hinges on imaging that shows demyelinating lesions in multiple CNS areas and, ideally, active inflammation. MRI with gadolinium is the most helpful test because it detects plaques in typical MS locations and, when contrast is used, highlights active lesions that are enhancing. This combination allows demonstration of dissemination in space ( lesions in multiple regions) and dissemination in time (new or enhancing lesions over time), which is central to confirming MS.

Lumbar puncture with oligoclonal bands can support the diagnosis, since these bands indicate intrathecal IgG synthesis, but they’re not specific to MS and can occur with other inflammatory conditions. EEG findings aren’t used to diagnose MS, and CT without contrast often misses MS plaques because they’re best visualized on MRI.